The Theme of Unity and Diversity in Mechanisms of Evolution
There's a party going on right here, and it's called life. Let's celebrate. It's all right. (All lessons should come with a soundtrack.)
Evolution has provided us with the ridiculously diverse planet. What's that? You want animals that glow in the dark? We've got that. Dracula snakes? We've got that, too. Underwater dragons? Here you go. There's more variety on Earth than can be seen in a lifetime, living on anything and everything imaginable. Every habitat on Earth is filled with different species of life. Life exists in some of the coldest, hottest, driest, wettest, and most acidic places on the planet. Hot Springs? Caves? Ocean Bottoms? Eh. No problemo. There's always a life form up for a challenge.
Diversity is endless. There are crazy anglerfish with glowing lanterns on their heads and lizards smaller than a penny. There are carnivorous plants and flowers that smell like rotting meat. There are us. There are all the bacteria that are living in us. Don’t' underappreciate the diversity around us either, from our backyard squirrels to those weeds that obviously want to party, too.
It's time to come together.
With all of our differences, it's easy to forget that we have a lot in common, too. Evolution is the study of how life forms have emerged from existing life. If we broke out our etch-a-sketch and started to draw the tree of life, we'd notice that organisms are classified into three domains: Archaea, Bacteria, and Eukarya. Eukarya is further divided into kingdoms that contain animals, plants, fungi, and protists. Don't let all these classifications fool you. There's plenty of unity between all life, and that's because we all evolved from a very distant common ancestor many, many millions of years ago. Like Archaea, Bacteria, and some Eukarya, this ancestor was probably a single-celled organism, too.
The three domains of life had a common ancestor or two.
Bacteria, humans, plants, yeast, cockroaches…we all naturally share some common characteristics that unify us. For example, all living things have DNA. All organisms also have the ability to pass on that genetic material to offspring. We all respond to stimuli, interact with our environment, grow, and perform fundamental processes, such as DNA replication, transcription, and protein translation. And thanks to Oprah, we all evolve.